Apparatus for securing heat sinks to a device under test

ABSTRACT

Apparatus and method for securing a heat sink to a heat-generating device on a circuit board. The apparatus clamps onto the heating-generating device and the circuit board in a manner that avoids bending of the circuit board. The apparatus includes a retention module having a plurality of retention features that extend through openings in the circuit board disposed about the perimeter of the heat-generating device, such as a processor. The apparatus also includes a heat sink having a heat sink base for contacting the heat-generating device in order to dissipate heat produced by the device. The heat sink is selectively securable to the retention features of the retention module using levers, such as a wire module, having a spring clip to engage the retention features and clamp the heat sink and retention module together.

This application is a continuation of U.S. Ser. No. 11/610,606 filed onDec. 14, 2006.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and apparatus for securing aheat sink above a central processing unit (CPU) of a computer.

2. Description of the Related Art

Heat sinks are a vital part of any computer system. The heat generatedby continued and extended use of a computer can severely damage theelectrical components in the computer. Heat sinks provide a way for theheat to be transferred away from the source and away from criticalcomponents. To increase the amount of thermal transfer, heat sinkstypically include a large surface area or a large number of thermallyconductive fins. However, the problem that arises when large heat sinksor heat sinks with a large number of fins are used is that criticalspace within the confines of the computer chassis is used up. Also,heavy heat sinks must be secured directly to the computer chassis inorder to avoid transmitting the direct weight of the heat sink on theCPU.

The contact area between the heat sink and the electrical components andthe pressure at the point of contact between the heat sink and the heatsource are also important considerations in heat sink design. A heatsink with a flat contact area is preferred since a thinner layer ofthermal compound may be used. This reduces the thermal resistancebetween the heat sink and the heat source. The pressure between the heatsink and the heat source must be high in order to maintain the requisitethermal contact and to facilitate thermal flow. Mechanical clips mayhelp maintain the requisite pressure between the surface of the heatsink and the CPU, but such clips are usually difficult to install andare not reliable when the computer is being shipped. Even a slightjarring during shipping may cause the weight of the heat sink to falldirectly on the CPU or motherboard causing severe damage. Further,because of the increased thickness in motherboards, the use of anunder-the-board spring to dampen the force exhibited by the heat sink onthe CPU and other electrical components is no longer feasible.

The recent proliferation of Land Grid Array (LGA) sockets have createdanother problem that must be considered during heat sink design andparticularly in the manner in which heat sinks or other cooling devicesare attached to the socket/CPU assembly. Current LGA socket designsfrequently contain heat sinks as part of the assembly. The heat sinkbase is usually used as one of the loading plates in the assembly and istypically attached to a back-side stiffener using multiple screws orspring-loaded threaded fasteners. Even these simple attachment means canconsume a significant portion of the effective heat sink volume, sincethe screws or spring-loaded fasteners protrude through the heat sink andrequire removal or partial removal of some of the fin structure, therebyreducing its thermal efficiency. Additionally, deflection that mightoccur under actuation load can create gaps between the heat sink and theassembly that can compromise the thermal effectiveness of the heat sinkand/or cause the weight of the heat sink to fall directly on the CPU.

It is therefore desirable to have an apparatus and method that allows aheat sink to be mounted above a CPU and to deliver a load commensuratewith the required thermal flow characteristics of the heat sink. Itwould also be desirable to provide a mechanism to hold the heat sinkfirmly in place without bending or imposing stresses upon the circuitboard or the processor. It would be even further desirable to attach theheat sink with a simple attachment mechanism.

SUMMARY OF THE INVENTION

The present invention provides an apparatus comprising a retentionmodule and a heat sink securable to a circuit board and aheat-generating device. The retention module has a retention module baseand a plurality of features extending upward from the retention modulebase about the perimeter of a heat-generating device secured to thecircuit board. The plurality of features includes first and secondopposing posts, each post including a retention feature or member. Theheat sink has a heat sink base and first and second levers pivotallysecured to opposing sides of the heat sink base. Each lever selectivelycauses a spring clip to engage the retention member. Preferably, theheat-generating device is secured to a first face of the circuit boardand the retention module base is disposed on an opposing face of thecircuit board with the plurality of features extending through openingsin the circuit board. The levers and spring clips are most preferablypart of a wire module that can be latched to secure the heat sink. Usingthe apparatus enables the heat sink to be selectively securable to theretention module for thermal communication with the heat-generatingdevice.

The present invention also provides a method comprising inserting firstand second retention features through openings in a circuit board from afirst side of the circuit board to a second side of the circuit boarduntil the first and second retention features are accessible on thesecond side of the circuit board on opposing sides of a heat generatingmember. The plurality of retention features are secured to a common basethat remains on the first side of the circuit board. The method alsocomprises securing a base of a heat sink to the first and secondretention features with the base in contact with the heat generatingdevice. Preferably, the step of securing includes clamping the retentionmodule and the heat sink with the circuit board and heat-generatingdevice there between. In one embodiment, activating the heat sinkretention assembly comprises rotating a wire module handle of the heatsink in order to engage the retention features of the retention module.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a processor secured to a motherboard.

FIG. 2 is a perspective view of a retention module.

FIG. 3 is a perspective view of the retention module having retentionfeatures extending through the motherboard about the perimeter of theprocessor.

FIG. 4 is a side view of the retention module extending through themotherboard as in FIG. 3.

FIG. 5 is a perspective view of a heat sink having a base and a pair oflevers.

FIG. 6A is a side view of the heat sink of FIG. 5 engaged with theupwardly extending features of the retention module.

FIG. 6B is a cross-sectional view of the heat sink and retention moduleof FIG. 6A taken along the line shown.

FIGS. 6C and 6D are cross-sectional views of the heat sink and theretention module, as shown in FIG. 6B, but including alternativefeatures in the retention module base.

FIG. 7 is a perspective view of heat sink of FIG. 6 engaged with theretention module and the lever partially actuated so that the clipengages the ramp.

FIG. 8 is a perspective view of heat sink of FIG. 6 engaged with theretention module and the lever fully actuated and latched to operativelysecure the heat sink in position.

DETAILED DESCRIPTION

The present invention provides an apparatus and method for securing aheat sink to a heat-generating device on a circuit board. The apparatusclamps onto the heating-generating device and the circuit board in amanner that avoids bending of the circuit board. The apparatus includesa retention module having a plurality of retention features that extendthrough openings in the circuit board disposed about the perimeter ofthe heat-generating device, such as a processor. The apparatus alsoincludes a heat sink having a heat sink base for contacting theheat-generating device in order to dissipate heat produced by thedevice. The heat sink is selectively securable to the retention featuresof the retention module using levers, such as a wire module, having aspring clip to engage the retention features and clamp the heat sink andretention module together.

The retention module has a retention module base and a plurality ofretention features extending from the retention module base about theperimeter of a heat-generating device secured to the circuit board.Preferably, the plurality of features includes first and second opposingposts that each includes a retention module for retaining a heat sink.Whereas the retention module and the heat-generating device may besecured to the same face of the circuit board, it is preferably todispose the retention module and heat-generating device on opposingfaces of the circuit board in order to apply more uniform forces thatwill not bend the circuit board. In this manner, the securing of theheat sink to the retention module clamps the heat-generating device andcircuit board there between.

Each post preferably has cross-sectional shape that allows it to beinserted through a hole in the circuit board. The posts are preferablyalso substantially parallel to allow them to be simultaneously insertedwithout significant flexing. After the posts are fully inserted, thebase should rest against a face of the circuit board in a uniform mannerto avoid bending or stressing the circuit board under a clamping force.Furthermore, the posts should be designed to extend through the circuitboard to allow access to a retention feature formed in or secured to theposts. Most preferably, the retention feature is integral with the postand is no greater in cross-section than the post that it is a part of.It is also preferably that the retention feature be formed on the distalend of the post and extend beyond the heat-generating device, such asextending above the upper surface of a processor. In one embodiment, thecircuit board openings are keyed to the plurality of retention features,such as posts, to ensure proper rotational orientation of the retentionmodule.

It is generally not necessary to independently attach the retentionmodule to the circuit board, such as with screws or adhesives. Rather,the retention module is inserted into openings through the circuit boardand initially prevented from displacement when the circuit board insecured in place, such as to a tray forming part of the chassis.Ultimately, the retention module is secured in its operative positionwhen a heat sink is secured to the retention features. In this operativeposition, the retention module and heat sink are drawn toward each otheruntil they are clamped about the circuit board and heat-generatingdevice. Accordingly, the heat sink base is urged against theheat-generating device and the retention module base is urged againstthe opposing face of the circuit board. It should be recognized thatintermediate elements could be juxtaposed between the retention modulebase and the circuit board or between the heat sink base and theheat-generating device without consequence to the invention, so long asthese intermediate elements do not prevent coupling of the heat sink tothe retention module and do not prevent heat transfer from theheat-generating device to the heat sink.

The retention module may also include one or more alignment post. Anysuch alignment post must also extend through an opening in the circuitboard to be received by the heat sink. For example, an alignment postmay be received by an alignment track formed in the heat sink base inorder to stabilize the position of the heat sink or ensure properorientation of the heat sink.

The heat sink has a heat sink base that will be placed in thermalcommunication with the heat-generating device. Typically, the exposedface of the heat-generating device will be planar and the exposed faceof the heat sink base will also be planar. This and other arrangementsfor full face-to-face contact provide good thermal communication betweenthe two components. Thermal grease or other thermally conductive orthermally enhancing materials may be juxtaposed there between, but arenot necessary. The heat sink base may include, without limitation, asolid metal or metal alloy plate, a thermally conductive composite, or avapor chamber. The heat sink base also secures heat dissipatingfeatures, such as cooling fins, heat pipes and the like, that extendinto an air flow passageway for cooling.

The heat sink further includes first and second levers pivotally securedto opposing sides of the heat sink base. Each of these leversselectively causes a spring clip to engage the retention memberextending through the circuit board. Accordingly, the heat sink isselectively securable to the retention module for thermal communicationof the heat sink with the heat-generating device.

The first and second levers of the heat sink align with the opposingfirst and second opposing posts of the retention module to ensure properorientation of the heat sink. Accordingly, the first lever aligns withone of the opposing posts and the second lever aligns with the otherpost. Preferably, the lever/post pairs are on completely opposite sidesof the heat-generating device in order to apply a uniform clamping forcewhen the heat sink is secured to the retention module.

In one embodiment, each retention module has a retention feature thatincludes a pivot groove for receiving a first arm of a spring clip and aretention ramp for receiving a second arm of a spring clip. In aparticularly preferred embodiment, the first and second levers andspring clips comprise a wire module having an upper handle section and alower pivoting section. The wire is advantageously made from a metalthat is resilient. The wire module is advantageously made from a singlepiece of metal to facilitate simultaneous movement of the levers formedby the wire module, enable a common latching mechanism, simplify thestructure necessary to pivotally couple the levers to the heat sink, andincorporate flexibility into the wire module.

In a particularly preferred embodiment illustrated in the drawingsbelow, the heat sink base includes a pivot groove for receiving thefirst arm of a spring clip and an arcuate arm capture channel forreceiving the second arm of the spring clip. The second arm of eachspring clip travels within an arm capture channel when the wire moduleis rotated or pivoted with respect to the heat sink pivot groove thatsecures the first arm of the spring clip. Preferably, the wire modulefurther includes end pins moveably retained by the arm capture channelto prevent accidental release of the first arm of the wire module fromthe arm capture channel. The arm capture channels have an arcuate shapeor path in order to allow the second arms to travel in an arc within thearm capture channels as the wire module is rotated.

The heat sink should also include a lever retainer to retain the leverin place after the spring clip has engaged the retention module. A greatnumber of means for retaining a lever in an actuated position are wellknown in the art. For example, the levers may be selectively secured intheir actuated position by a latch that holds some portion of the leveror a small notch in the retention ramp that provides a stable positionfor the second arm of the spring clip when the second arm has reached alatched position. In one embodiment, a wire module is rotatable from anon-latching position where the second arm is not engaged with theretention ramp of the retention module to a latching position where thesecond arm engages the retention ramp such that when the wire module isin the latching position, the heat sink is secured to the retentionmodule while maintaining contact with heat-generating device therebetween.

The present invention also includes a method of securing a heat sink toa heat-generating device on a circuit board. The method includesinserting first and second retention features through openings in acircuit board from a first side of the circuit board to a second side ofthe circuit board until the first and second retention features areaccessible on the second side of the circuit board on opposing sides ofa heat generating member. The plurality of retention features aresecured to a common retention module base that remains on the first sideof the circuit board. The method then includes securing a base of a heatsink to the first and second retention features with the base in contactwith the heat generating device. Preferably, the heat sink maintainscontact with the electrical component while transmitting the load of theheat sink to the heat sink retention assembly.

The step of securing preferably includes clamping the retention moduleand the heat sink with the circuit board and heat-generating devicethere between. In a specific embodiment, the step of securing comprisesrotating a wire module handle of the heat sink in order to engage theretention features of the retention module. The wire module engages theopposing retention features to secure the base of the heat sink to theretention module. The specific interactions of the wire module with theretention module and the heat sink will be described in more detail withreference to the figures that follow.

FIG. 1 is a perspective view of a processor 10 secured to a motherboard12 via a socket 11. The processor 10 is also provided with electroniccommunication with other components (not show) in a manner facilitatedby the socket 11 and the motherboard 12. The motherboard 12 is itselfsecured to a sheet metal tray 14 at various points to provide physicalsupport and protection to the motherboard. The motherboard 12 is shownwith a set of holes or openings 13 around the perimeter of the process10 and socket 11.

FIG. 2 is a perspective view of a retention module. The retention module20 includes a base 22 and a plurality of upwardly extending features.The features include first and second opposing retention posts 24 andfirst and second alignment posts 26. Each retention post 24 has aretention feature 28, preferably at the distal end of the retentionpost, for selectively securing a heat sink. As shown, the retentionfeature 28 includes a pivot groove 30 in a known spaced relationship toa retention ramp 32. The retention ramp 32 is preferably formed as theslanted upper surface of a slot formed at an angle to axis of theretention post 24.

Whereas the retention features 28 operate to secure a heat sink, thealignment features 26 are intended to prevent improper alignment of theheat sink with respect to the retention module and perhaps provide someadded degree of stability to the assembly. For example, one alignmentfeature 26 includes a tip 34 having a square-shaped cross-section andanother alignment feature 26 includes a tip 36 having a round-shapedcross-section. These tips 34, 36 should exclusively mate with matchingholes or openings in the heat sink in order to dictate the orientationof the heat sink.

Both the retention posts 24 and the alignment posts 26 may includeover-travel rests or shoulders 38 to prevent any one side of a heat sinkfrom dropping too low during initial coupling of the heat sink. However,the shoulders 38 are not intended to support the heat sink once the heatsink is secured to the retention module.

FIG. 3 is a perspective view of features 24, 26 extending from theretention module base (not shown) through the holes 13 in themotherboard 12 that are positioned about the perimeter of the processor10, including its socket 11.

FIG. 4 is a side view of the retention module 20 with the features 24,26 extending through the motherboard 12 as in FIG. 3. The features 24,26 extend beyond the surface of the processor 10 in order to beaccessible for aligning and securing a heat sink.

FIG. 5 is a perspective view of a heat sink 40 having a base 42 andfirst and second levers 44. As shown, the two levers 44 are part of anintegral wire module that also includes an upper handle 46 and springclips 48 (partially shown) near the two distal ends. The heat sink 40 isaligned for engagement with the features 24, 26 of the retention module,but not yet positioned for securing. A side bracket 52 includes a pivotgroove 51 and a slot 54 that pivotally secure the wire module to theheat sink 40.

It should be noted that the tip 34 having a square-shaped cross-sectionis aligned to be received by a similar square-shaped hole 50 in the heatsink base 42. This keyed relationship ensures that the heat sink 40 willbe oriented in an appropriate or intended relationship to the retentionmodule, which is itself preferably keyed to the motherboard. While someheat sink designs may not require a particular orientation, other heatsinks, such as those having vertically-oriented fins, may operate poorlyunless specifically oriented with respect to the intended airflowthrough a chassis in which the components will be installed.

FIG. 6A is a side view of the heat sink 40 of FIG. 5 engaged with theupwardly extending features 24, 26 of the retention module 20. The wiremodule comprises an upper handle 46, levers 44 and spring clips 48. Thelevers 44 pivot about the pivot groove 30 formed in a side bracket 52. Afirst arm of the spring clip 48 extends through the pivot groove 30(toward the heat sink). A second arm of the spring clip 48 extendsthrough a slot 54 in the side bracket 52 (away from the heat sink). Theend 56 of the spring clip 48 is preferably turned to prevent the secondarm of the spring clip 48 from drawing out of the slot 54. Although theretention feature 24 is hidden in this view (dashed lines), the firstarm of the spring clip 48 is also received in the pivot groove 30 andthe second arm of the spring clip 48 is positioned at the entry to theretention ramp 32 (See also FIG. 2).

FIG. 6B is a cross-sectional view of the heat sink 40 and retentionmodule 20 of FIG. 6A taken along the line shown. In this embodiment, thewire module is shown in its entirety to include the upper handle 46,first and second levers 44, and spring clips 48. In this view, thespring clips 48 are easily seen as having a sideways “U-shaped” bend inthe wire. First (upper) arms 58 of the two spring clips 48 are disposedin both the heat sink bracket pivot groove 51 and the retention modulepivot groove 30. Pivoting the wire module in grooves 30, 51 allows thefirst (upper) arms 58 to ride up and down in the groove as the wiremodule is flexed, yet the grooves provide lateral support for pivotingthe wire module. Specifically, the first (upper) arm 58 (as seen in theside view of FIG. 6A) will bear against the right side of the pivotgroove 51 as the upper handle 46 is moved to the right, particularly asthe second (lower) arm 60 encounters resistance. Second (lower) arms 60of the two spring clips 48 are disposed in the heat sink bracket slots54 and selectively disposed in the slots that define the retention ramps32 in the retention module 20.

As the wire module is pivoted (as shown in progression from FIG. 6A toFIG. 7 to FIG. 8), the wire module flexes, probably in more than onedimension and possibly in a complex manner. It is believed that thelevers 44 flex and bend roughly within a plane generally perpendicularto the axis about which the wire module pivots and that the arms 58, 60flex and bend roughly in a plane that includes the pivot axis. In anyevent, the wire module interacts in a cooperative manner with thegrooves 30, 51 and ramps/slots 32, 54. It is further believed, althoughthe invention is not so limited, that the clamping force drawing theheat sink and the retention module toward each other in this embodimentis caused by “wedging” or “driving” the second (lower) spring clip arm60 between the retention ramp 32 and the lower edge of the heat sinkbracket slot 54.

As shown, when the heat sink is positioned for securing to the retentionmodule, the retention ramp 32 slopes downward and intersects the slot54. Although the slot adjacent the retention ramp 32 and the heat sinkbracket slot 54 are both individually wide enough for the second arm topass freely, the intersection of the two slots causes a gradualnarrowing of the spacing between the retention ramp 32 (on the top) andthe lower edge of the slot 54 (on the bottom). As the wire module ispivoted to secure the heat sink, the second spring clip arm 60 is forcedbetween the ramp 32 and the lower edge of the slot 54 to bias the heatsink downward and the retention module upward. The gradual narrowing ofthe of the space between ramp 32 and slot 54 causes the arm 60 toencounter gradually increasing resistance as the wire module is fullypivoted and latched in a closed position. As the resistance to furthermovement of the arm 60 increases, the wire module will flex sufficientlyto allow the latching of the upper handle 46. Accordingly, it is the“spring constant” of the wire module that determines the extent of thewedging force between the ramp 32 and the slot 54 and, ultimately, theclamping force of the heat sink against the processor. Accordingly, aclamping force within a narrow predefined range can be applied evenwhile accommodating some variation in the height of the processor. Solong as the pivot grooves 30, 51 are sufficient deep to retain the arms58, 60 of the spring clip, and those arms are sufficient spaced to avoidbinding up, then he extent of the processor height variation that can beaccommodated is primarily a function of the relative pitch and run ofthe overlapping ramp 32 and slot 54. In other words, the overlappingramp and slot must produce a narrowing channel, in which the arm can bereceived and wedged, over the entire range of processor heights thatneed to be accommodated. This tolerance for varying height may allow thesame retention module and heat sink combination to be used inconjunction with different heat-generating devices or at leastaccommodate manufacturing variations from one installation to another.

It should be recognized from FIG. 6B, that the clamping forces appliedbetween the heat sink base 42 and the rentention module base 22, ifsufficiently large, could cause the circuit board 12 to bow downward inthe central region below the processor 10 since this region isunsupported. This potential for bowing can be controlled by limiting theapplied clamping force, using a stiff circuit board, or providing acentral support member. Still, there may be applications where a slightbowing of the circuit board is desirable.

FIGS. 6C and 6D are cross-sectional views of the heat sink and theretention module, as shown in FIG. 6B, but including alternativefeatures in the retention module base. Specifically, FIG. 6C shows theretention module base 42 including a central support arm 43 having anupper surface forming a central stud 45. The central stud 45 isbeneficial to prevent downward bowing of circuit board 12 in the regionunder the processor 10. FIG. 6D shows the retention module base 42including a central arm 43 positioning a pair of outwardly biasedmembers 47 secured about the ends of a spring 49. The outwardly biasedmembers 47 push upward against the circuit board 12 and downward againstthe chassis 14, respectively. The outwardly biased members 47 may bebeneficially employed to impart an upward bow to the circuit board 12,either before or after installation of the heat sink 40.

FIG. 7 is a perspective view of the heat sink 40 of FIG. 6 engaged withthe retention module 20 and the lever 44 partially actuated so that thesecond arm 60 of the spring clip 48 has entered and engaged theretention ramp 32.

FIG. 8 is a perspective view of heat sink 40 of FIG. 6 engaged with theretention module 20 and the lever 44 fully actuated so that the secondarm 60 of the spring clip 48 has applied a clamping bias between theheat sink bracket pivot groove 51 and retention module retention ramp32. The upper handle 46 of the wire module is secured in a latch groove80 to operatively secure the heat sink in position. The heat sink 40 canbe removed by disengaging the upper handle 46 from the latch groove 80and moving the wire module back to the position shown in FIG. 6A.

The terms “comprising,” “including,” and “having,” as used in the claimsand specification herein, shall be considered as indicating an opengroup that may include other elements not specified. The term“consisting essentially of,” as used in the claims and specificationherein, shall be considered as indicating a partially open group thatmay include other elements not specified, so long as those otherelements do not materially alter the basic and novel characteristics ofthe claimed invention. The terms “a,” “an,” and the singular forms ofwords shall be taken to include the plural form of the same words, suchthat the terms mean that one or more of something is provided. The term“one” or “single” may be used to indicate that one and only one ofsomething is intended. Similarly, other specific integer values, such as“two,” may be used when a specific number of things is intended. Theterms “preferably,” “preferred,” “prefer,” “optionally,” “may,” andsimilar terms are used to indicate that an item, condition or step beingreferred to is an optional (not required) feature of the invention.

It will be understood from the foregoing description that variousmodifications and changes may be made in the preferred embodiment of thepresent invention without departing from its true spirit. It is intendedthat this description is for purposes of illustration only and shouldnot be construed in a limiting sense. The scope of this invention shouldbe limited only by the language of the following claims.

1. An apparatus comprising: a retention module retained in positionrelative to a circuit board, the retention module having a retentionmodule base and a plurality of features extending upward from theretention module base about the perimeter of a heat-generating devicesecured to the circuit board, wherein the plurality of features includesfirst and second opposing posts, the first post including a firstretention member and the second post include a second retention member;and a heat sink having a heat sink base and first and second leverspivotally secured to opposing sides of the heat sink base, each leverhaving a spring clip and selectively causing the spring clip to engageone of the retention members, wherein the heat sink is selectivelysecurable to the retention module for thermal communication with theheat-generating device.
 2. The apparatus of claim 1, wherein theplurality of features further includes one or more alignment post, andwherein the heat sink base includes one or more alignment hole forreceiving the one or more alignment post.
 3. The apparatus of claim 1,wherein the heat-generating device is secured to a first face of thecircuit board and the retention module base is disposed on an opposingface of the circuit board with the plurality of features extendingthrough openings in the circuit board.
 4. The apparatus of claim 3,wherein the securing of the heat sink to the retention module clamps theheat-generating device and circuit board there between.
 5. The apparatusof claim 3, wherein the circuit board openings are keyed to theplurality of features to ensure proper orientation of the retentionmodule.
 6. The apparatus of claim 3, wherein the first and second leversof the heat sink align with the opposing first and second opposing postsof the retention module to ensure proper orientation of the heat sink.7. The apparatus of claim 1, wherein each retention member includes apivot groove for receiving a first arm of the spring clip and aretention ramp for receiving a second arm of the spring clip.
 8. Theapparatus of claim 7, wherein the first and second levers and springclips comprise a wire module having an upper handle section and a lowerpivoting section.
 9. The apparatus of claim 8, wherein the heat sinkbase includes a pivot groove for receiving the first arm and an armcapture channel for receiving the second arm such that the second armtravels within the channel when the wire module is rotated with respectto the heat sink pivot groove.
 10. The apparatus of claim 9, wherein thewire module further includes end pins moveably retained by the armcapture channel to prevent accidental release of the first arm of thewire module from the arm capture channel.
 11. The apparatus of claim 9,wherein the arm capture channel and the retention ramp intersect so thatpivoting the wire module biases the second arm between the retentionramp and arm capture channel and clamps the heat sink to the retentionmodule.
 12. The apparatus of claim 1, wherein the heat sink furthercomprises a lever retainer to retain each lever in place after thespring clip has engaged the retention module.
 13. The apparatus of claim8, wherein the wire module is rotatable from a non-latching positionwhere the second arm is not engaged with the retention ramp of theretention module to a latching position where the second arm engages oneof the retention ramp such that when the wire module is in the latchingposition, the heat sink is secured to the retention module whilemaintaining contact with heat-generating device there between.
 14. Theapparatus of claim 1, wherein the heat sink is securable to theretention module with tolerance for variability in the thickness of theheat-generating device.
 15. The apparatus of claim 8, furthercomprising: a latch for selectively securing the wire module in aposition with the second arm of each spring clip engaging the retentionramp of one of the retention members.
 16. A method comprising: insertingfirst and second retention features through separate openings in acircuit board from a first side of the circuit board to a second side ofthe circuit board until the first and second retention features areaccessible on the second side of the circuit board on opposing sides ofa heat generating device, wherein the plurality of retention featuresare secured to a common base that remains on the first side of thecircuit board, securing a base of a heat sink to the first and secondretention features with the base in contact with the heat generatingdevice.
 17. The method of claim 16, wherein the heat sink maintainscontact with the heat-generating device while transmitting the load ofthe heat sink to the first and second retention features.
 18. The methodof claim 16, wherein the step of securing includes clamping the commonbase and the heat sink with the circuit board and the heat-generatingdevice there between, and wherein clamping the common base and the heatsink comprises: rotating a wire module handle of the heat sink in orderto engage the retention features.
 19. The method of claim 18, whereinthe wire module engages the opposing retention features to secure thebase of the heat sink.